When after-acquired collateral is encumbered by more than one security interest, one of the security interests often is a purchase-money security interest that is entitled to special priority under Section 9-324 [Maine cite section 9-1324].

6. Priority in Proceeds: General Rule. Subsection (b)(1) [Maine cite subsection (2), paragraph (a)] follows former Section 9-312(6). It provides that the baseline rules of subsection (a) [Maine cite subsection (1)] apply generally to priority conflicts in proceeds except where otherwise provided (e.g., as in subsections (c) through (e) [Maine cite subsections (3) to (5)]). Under Section 9-203 [Maine cite section 9-1203], attachment cannot occur (and therefore, under Section 9-308 [Maine cite section 9-1308], perfection cannot occur) as to particular collateral until the collateral itself comes into existence and the debtor has rights in it. Thus, a security interest in proceeds of original collateral does not attach and is not perfected until the proceeds come into existence and the debtor acquires rights in them.

Example 5: On April 1, Debtor authenticates a security agreement granting to A a security interest in all Debtor's existing and after-acquired inventory. The same day, A files a financing statement covering inventory. On May 1, Debtor authenticates a security agreement granting B a security interest in all Debtor's existing and future accounts. On June 1, Debtor sells inventory to a customer on 30-day unsecured credit. When Debtor acquires the account, B's security interest attaches to it and is perfected by B's financing statement. At the very same time, A's security interest attaches to the account as proceeds of the inventory and is automatically perfected. See Section 9- 315 [Maine cite section 9-1315]. Under subsection (b) [Maine cite subsection (2)] of this section, for purposes of determining A's priority in the account, the time of filing as to the original collateral (April 1, as to inventory) is also the time of filing as to proceeds (account). Accordingly, A's security interest in the account has priority over B's. Of course, had B filed its financing statement on before A filed (e.g., on March 1), then B would have priority in the accounts.

Section 9-324 [Maine cite section 9-1324] governs the extent to which a special purchase-money priority in goods or software carries over into the proceeds of the original collateral.